One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,7)(4,8)(5,6)(9,10)(11,17)(12,16)(13,14)(15,19)(18,24)(20,22)(21,23)(25,26)(27,34)(28,32)(29,31)(30,33)(35,40)(36,38)(37,39) involution — undirected(2,6)(3,8)(10,14)(15,17)(16,20)(23,24)(25,27,30,29)(26,31,33,34)(28,35,36,37)(32,39,38,40)(1,3)(2,4)(5,8)(6,7)(10,14)(15,17)(16,20)(23,24)(28,36)(32,38)(35,37)(39,40) involution — undirected(1,3)(2,4)(5,8)(6,7)(9,10)(11,15)(12,20)(13,14)(16,22)(17,19)(18,24)(21,23)(25,28,30,36)(26,32,33,38)(27,35,29,37)(31,39,34,40)(1,4)(2,3)(5,7)(6,8)(9,11)(10,15)(12,21)(13,19)(14,17)(16,24)(18,22)(20,23)(25,29,30,27)(26,31,33,34)(28,37,36,35)(32,39,38,40)(9,12)(10,16)(11,18)(13,22)(14,20)(15,23)(17,24)(19,21)(25,26)(27,31)(28,38)(29,34)(30,33)(32,36)(35,40)(37,39) involution — undirectedA Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.